FTIR-ATR spectroscopy applied to quality control of grape-derived spirits

• Autor(a) principal: Anjos, Ofélia
• Data de Publicação: 2016
• Outros Autores: Santos, António J.A., Estevinho, Leticia M., Caldeira, Ilda
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/15325
• topic: Alcoholic strength; Attenuated total reflectance; Fourier transform infrared spectroscopy; Fusel alcohols; Grape-derived spirits; Methanol

The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400 cm -1 ) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r 2 = 99.4; RPD = 12.8), alcoholic strength (r 2 = 97.2; RPD = 6.0), acetaldehyde (r 2 = 98.2; RPD = 7.5) and fusel alcohols (r 2 from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis.